Bronchoscopy and Esophagoscopy / A Manual of Peroral Endoscopy and Laryngeal Surgery

by Chevalier Jackson

[117] CHAPTER XI—ACQUIRING SKILL

Endoscopic ability cannot be bought with the instruments. As with all mechanical procedures, facility can be obtained only by educating the eye and the fingers in repeated exercise of a particular series of maneuvers. As with learning to play a musical instrument, a fundamental knowledge of technic, positions, and landmarks is necessary, after which only continued manual practice makes for proficiency. For instance, efficient use of forceps requires that they be so familiar to the grasp that their use is automatic. Endoscopy is a purely manual procedure, hence to know how is not enough: manual practice is necessary. Even in the handling of the electrical equipment, practice in quickly locating trouble is as essential as theoretic knowledge. There is no mystery about electric lighting. No source of illumination other than electricity is possible for endoscopy. Therefore a small amount of electrical knowledge, rendered practical by practice, is essential to maintain the simple lighting system in working order. It is an insult to the intelligence of the physician to say that he cannot master a simple problem of electric testing involving the locating of one or more of five possibilities. It is simply a matter of memorizing five tests. It is repeated for emphasis that a commercial current reduced by means of a rheostat should never be used as a source of current for endoscopy with any kind of instrument, because of the danger to the patient of a possible "grounding" of the circuit during the extensive moist contact of a metallic endoscopic tube in the mediastinum. The battery shown in Fig. 8 should be used. The most frequent cause of trouble is the mistake of over-illuminating the lamps. The lamp should not be over-illuminated to the dazzling whiteness usually used in flash lights. Excessive illumination alters the proper perception of the coloring of the mucosa, besides shortening the life of the lamps. The proper degree of brightness is obtained when, as the current is increased, the first change from yellow to white light is obtained. Never turn up the rheostat without watching the lamp.

Testing for Electric Defects.—These tests should be made beforehand; not when about to commence introduction.

If the first lamp lights up properly, use it with its light-carrier to test out the other cords.

If the lamp lights up, but flickers, locate the trouble before attempting to do an endoscopy. If shaking the carrier cord-terminal produces flickering there may be a film of corrosion on the central contact of the light carrier that goes into the carrier cord-terminal.

If the lamp fails to show a light, the trouble may be in one of five places which should be tested for in the following order and manner. 1. The lamp may not be firmly screwed into the light-carrier. Withdraw the light-carrier and try screwing it in, though not too strongly, lest the central wire terminal in the lamp be bent over. 2. The light-carrier may be defective. 3. The cord may be defective or its terminals not tight in the binding posts. If screwing down the thumb nuts does not produce a light, test the light-carrier with lamp on the other cords. Reserve cords in each pair of binding posts are for use instead of the defective cords. The two sets of cords from one pair of binding posts should not be used simultaneously. 4. The lamp may be defective. Try another lamp. 5. The battery may be defective. Take a cord and light-carrier with lamp that lights up, detaching the cord-terminals at the binding posts, and attach the terminals to the binding posts of the battery to be tested.

Efficient use of forceps requires previous practice in handling of the forceps until it has become as natural and free from thought as the use of knife and fork. Indeed the coordinate use of the bronchoscopic tube-mouth and the forceps very much resembles the use of knife and fork. Yet only too often a practitioner will telegraph for a bronchoscope and forceps, and without any practice start in to remove an entangled or impacted foreign body from the tiny bronchi of a child. Failure and mortality are almost inevitable. A few hundred hours spent in working out, on a bit of rubber tubing, the various mechanical problems given in the section on that subject will save lives and render easily successful many removals that would otherwise be impossible.

It is often difficult for the beginner to judge the distance the forceps have been inserted into the tube. This difficulty is readily solved if upon inserting the forceps slowly into the tube, he observes that as the blades pass the light they become brightly illuminated. By this light reflex it is known, therefore, that the forceps blades are at the tube-mouth, and distance from this point can be readily gauged. Excellent practice may be had by picking up through the bronchoscope or esophagoscope black threads from a white background, then white threads from a black background, and finally white threads on a white background and black threads on a black background. This should be done first with the 9 mm. bronchoscope. It is to be remembered that the majority of foreign body accidents occur in children, with whom small tubes must be used; therefore, practice work, after say the first 100 hours, should be done with the 5 mm. bronchoscope and corresponding forceps rather than adult size tubes, so that the operator will be accustomed to work through a small calibre tube when the actual case presents itself.

[120] Cadaver Practice.—The fundamental principles of peroral endoscopy are best taught on the cadaver. It is necessary that a specially prepared subject be had, in order to obtain the required degree of flexibility. Injecting fluid of the following formula worked out by Prof. J. Parsons Schaeffer for the Bronchoscopic Clinic courses, has proved very satisfactory: Sodium carbonate—1 1/2 lbs. White arsenic—2 1/2 lbs. Potassium nitrate—3 lbs. Water—5 gal.

Boil until arsenic is dissolved. When cold add:
Carbolic acid 1500 c.c.
Glycerin 1250 c.c.
Alcohol (95%) 1250 c.c.

For each body use about 3 gal. of fluid.

The method of introduction of the endoscopic tube, and its various positions can be demonstrated and repeatedly practiced on the cadaver until a perfected technic is developed in both the operator and assistant who holds the head, and the one who passes the instruments to the operator. In no other manner can the landmarks and endoscopic anatomy be studied so thoroughly and practically, and in no other way can the pupil be taught to avoid killing his patient. The danger-points in esophagoscopy are not demonstrable on the living without actually incurring mortality. Laryngeal growths may be simulated, foreign body problems created and their mechanical difficulties solved and practice work with the forceps and tube perfected.

Practice on the Rubber-tube Manikin.—This must be carried out in two ways. 1. General practice with all sorts of objects for the education of the eye and the fingers. 2. Before undertaking a foreign body case, practice should be had with a duplicate of the foreign body.

It is not possible to have a cadaver for daily practice, but fortunately the eye and fingers may be trained quite as effectually by simulating foreign body conditions in a small red rubber tube and solving these mechanical problems with the bronchoscope and forceps. The tubing may be placed on the desk and held by a small vise (Fig. 72) so that at odd moments during the day or evening the fascinating work may be picked up and put aside without loss of time. Complicated rubber manikins are of no value in the practice of introduction, and foreign body problems can be equally well studied in a piece of rubber tubing about 10 inches long. No endoscopist has enough practice on the living subject, because the cases are too infrequent and furthermore the tube is inserted for too short a space of time. Practice on the rubber tube trains the eye to recognize objects and to gauge distance; it develops the tactile sense so that a knowledge of the character of the object grasped or the nature of the tissues palpated may be acquired. Before attempting the removal of a particular foreign body from a living patient, the anticipated problem should be simulated with a duplicate of the foreign body in a rubber tube. In this way the endoscopist may precede each case with a practical experience equivalent to any number of cases of precisely the same kind of foreign body. If the object cannot be removed from the rubber tube without violence, it is obvious that no attempt should be made on the patient until further practice has shown a definite method of harmless removal. During practice work the value of the beveled lip of the bronchoscope and esophagoscope in solving mechanical problems will be evidenced. With it alone, a foreign body may be turned into favorable positions for extraction, and folds can always be held out of the way. Sufficient combined practice with the bronchoscope and the forceps enable the endoscopist easily to do things that at first seem impossible. It is to be remembered that lateral motion of the long slender tube-forceps cannot be controlled accurately by the handle, this is obtained by a change in position of the endoscopic tube, the object being so centered that it is grasped without side motion of the forceps. When necessary, the distal end of the forceps may be pushed laterally by the manipulation of the bronchoscope.

[FIG. 72.—A simple manikin. The weight of the small vise serves to steady the rubber tubing. By the use of tubing of the size of the invaded bronchus and a duplicate of the foreign body, any mechanical problem can he simulated for solution or for practice, study of all possible presentations, etc.]

Practice on the Dog.—Having mastered the technic of introduction on the cadaver and trained the eye and fingers by practice work on the rubber tube, experience should be had in the living lower air and food passages with their pulsatory, respiratory, bechic and deglutitory movements, and ever-present secretions. It is not only inhuman but impossible to obtain this experience on children. Fortunately the dog offers a most ready subject and need in no way be harmed nor pained by this invaluable and life-saving practice. A small dog the size of a terrier (say 6 to 10 pounds in weight) should be chosen and anesthetized by the hypodermic injection of morphin sulphate in dosage of approximately one-sixth of a grain per pound of body weight, given about 45 minutes before the time of practice. Dogs stand large doses of morphin without apparent ill effect, so that repeated injection may be given in smaller dosage until the desired degree of relaxation results. The first effect is vomiting which gives an empty stomach for esophagoscopy and gastroscopy. Vomiting is soon followed by relaxation and stupor. The dog is normal and hungry in a few hours. Dosage must be governed in the clog as in the human being by the susceptibility to the drug and by the temperament of the animal. Other forms of anesthesia have been tried in my teaching, and none has proven so safe and satisfactory. Phonation may be prevented during esophagoscopy by preventing approximation of the cords, through inserting a silk-woven cathether in the trachea. The larynx and trachea may be painted with cocain solution if it is found necessary for bronchoscopy. A very comfortable and safe mouth gag is shown in Fig. 73. Great gentleness should be exercised, and no force should be used, for none is required in endoscopic work; and the endoscopist will lose much of the value of his dog practice if he fails to regard the dog as a child. He should remember he is not learning how to do endoscopy on the dog; but learning on the dog how safely to do bronchoscopy on a human being. The degree of resistance during introduction can be gauged and the color of the mucosa studied, while that interesting phenomenon, the dilatation and lengthening of the bronchi during inspiration and their contraction and shortening during expiration, is readily observed and always forms subject for thought in its possible connection with pathological conditions. Foreign body problems are now to be solved under these living conditions, and it is my feeling that no one should attempt the removal of a foreign body from the bronchus of a child until he has removed at least 100 foreign bodies from the dog without harming the animal. Dogs have the faculty of easily ridding their air-passages of foreign objects, so that one need not be alarmed if a foreign body is lost during practice removal. It is to be remembered that dogs swallow very large objects with apparent ease. The dog's esophagus is relatively much larger than that of human beings. Therefore a small dog (of six to eight pounds' weight) must be used for esophagoscopic practice, if practice is to be had with objects of the size usually encountered in human beings. The bronchi of a dog of this weight will be about the size of those of a child.

[FIG. 73.—Author's mouth gag for use on the dog. The thumb-nut serves to prevent an uncomfortable degree of expansion of the gag. A bandage may be wound around the dog's jaws to prevent undue spread of the jaws.]

Endoscopy on the Human Being.—Dog work offers but little practice in laryngoscopy. Because of the slight angle at which the dog's head joins his spine, the larynx is in a direct line with the open mouth; hence little displacement of the anterior cervical tissues is necessary. Moreover the interior of the larynx of the dog is quite different from that of the human larynx. The technic of laryngoscopy in the human subject is best perfected by a routine direct examination of the larynx of anesthetized patients after such an operation as, for instance, tonsillectomy, to see that the larynx and laryngopharynx are free of clots. To perform a bronchoscopy or esophagoscopy under these conditions would be reprehensible; but direct laryngoscopy for the seeking and removal of clots serves a useful purpose as a preventative of pulmonary abscess and similar complications.* Diagnosis of laryngeal conditions in young children is possible only by direct laryngoscopy and is neglected in almost all of the cases. No anesthesia, general or local, is required. Much clinical material is neglected. All cases of dyspnea or dysphagia should be studied endoscopically if the cause of the condition cannot be definitely found and treated by other means. Invaluable practice in esophagoscopy is found in the treatment of strictures of the esophagus by weekly or biweekly esophagoscopic bouginage.

* Dr. William Frederick Moore, of the Bronchoscopic Clinic, has recently collected statistics of 202 cases of post-tonsillectomic pulmonary abscess that point strongly to aspiration of infected clots and other infective materials as the most frequent etiologic mechanism (Moore, W. F., Pulmonary Abscess. Journ. Am. Med. Assn., April 29, 1922, Vol. 78, pp. 1279-1281).

In acquiring skill as an endoscopist the following paraphrased aphorisms afford food for thought.

APHORISMS

Educate your eye and your fingers.
Be sure you are right, but not too sure.
Follow your judgment, never your impulse.
Cry over spilled milk enough to memorize how you spilled it.
Let your mistakes worry you enough to prevent repetition.
Let your left hand know what your right hand does and how
to do it.
Nature helps, but she is no more interested in the survival of your
patient than in the survival of the attacking pathogenic bacteria.